Conventionally, probabilistic models and software tools based thereupon have been used to quantify the reliability of networks and network services for engineering design and network planning. Such models take into account, for example, hardware/software failures and link/node processes using mathematical processes such as renewal processes, Markovian models, Markov chains, Markov processes, and combinatorial reliability. Many natural or man-made events can also lead to system and service failures. Such events, however, are difficult to model and/or quantify mathematically. Examples of such events may include hurricanes, meteor strikes, ice storms, tornadoes, earthquakes, unforeseen catastrophic software events, terrorist/criminal attacks, and combinations thereof. Although such events are unlikely and combinations thereof are even more unlikely, such events can still occur. As society becomes increasingly dependent upon networks and network services (e.g., internet service, video service, cellular service, messaging services, E911, etc.) it is becoming increasingly desirable to design and build networks and network services to survive combinations of failures despite their unlikelihood.
These and other embodiments and advantages will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the various exemplary embodiments.